The invention relates to a device for the discontinuous production of block foam wherein a bridge-like framework, is equipped with a vertically movable mixing unit, which is provided with component feed lines and a stirrer. The mixing unit has as a mixing container a bottomless cylindrical shell which can be mounted to a plate having feed openings for the reaction components. A distributing device is arranged underneath the feed opening for one of the reaction components. The mixing unit is vertically movable into and/or out of a mold placed beneath the mixing container. Equipment of this type is advantageous for the discontinuous production of block foam, when insufficient product requirements make continuous production unprofitable.
The mixing of the components is a particularly critical factor with equipment for discontinuous production techniques. With known equipment the components are simply introduced through a plate at the top of the mixing container and stirred. After each mixing operation, the interior wall of the mixing container has to be cleaned manually. A more refined version has a distribution channel at the upper edge of the mixing container, from the bottom of which an annular gap opens toward the interior wall of the mixing container. The mixing container is provided with a floor which has a lockable opening. In introducing the components through the feed openings into the mixing container, one component is fed in first through the distribution channel. This first component is distributed around the circumference of the interior wall of the mixing container and runs down the wall thereby rinsing it. Only then is the second component fed through the other feed opening, without using the distribution channel. Such a mixing container, therefore, is costly because of the necessary distribution channel and the container floor having a lockable exit opening. The flushing procedure is relatively time consuming, because the annular gap may not exceed a certain maximum width to assure the distribution of the components over the entire ring cavity of the distribution channel so that all wall sections are flushed uniformly. Flushing of the exit opening in the floor results in significant material losses.
It is an object of the invention to safely flush the interior walls of the mixing container within the shortest possible time, using relatively simple means. It is also an object of the invention to avoid flushing and to avoid additional areas which cannot be flushed and where the mixture could settle.